Center for Environment and Marine Studies, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia.
Center for Environment and Marine Studies, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia.
Mar Pollut Bull. 2023 May;190:114801. doi: 10.1016/j.marpolbul.2023.114801. Epub 2023 Mar 23.
Survival in the early life stages is a major factor determining the growth and stability of wildlife populations. For sea turtles, nest location must provide favorable conditions to support embryonic development. Hatching success and incubation environment of green turtle eggs were examined in July 2019 at Karan Island, a major nesting site for the species in the Arabian Gulf. Mean hatching success averaged at 38.8 % (range = 2.5-75.0 %, n = 14). Eggs that suffered early embryonic death (EED) and late embryonic death (LED) represented 19.8 % (range: 3.3-64.2 %) and 41.4 % (range: 4.8-92.6 %) of the clutch on average, respectively. Nest sand was either coarse (0.5-1 mm: mean 44.8 %, range = 30.4-56.9 % by dry weight, n = 14) or medium (0.25-0.5 mm: mean 33.6 %, range = 12.0-45.5 % by dry weight, n = 14). Mean sand moisture (4.0 %, range = 3.2-4.9 %, n = 14) was at the lower margin for successful development. Hatching success was significantly higher in clutches with sand salinity <1500 EC.uS/cm (n = 5) than those above 2500 EC.uS/cm (n = 5). Mean clutch temperatures at 1200 h increased by an average of 5.4 °C during the 50-d post-oviposition from 31.2 °C to 36.6 °C. Embryos experienced lethally high temperatures in addition to impacts of other environmental factors (salinity, moisture, sand grain size), which was related to reduced hatching success. Conservation initiatives must consider the synergistic influence of the above parameters in formulating strategies to improve the overall resilience of the green turtle population in the Arabian Gulf to anthropogenic and climate change-related stressors.
早期生命阶段的存活率是决定野生动物种群增长和稳定性的主要因素。对于海龟来说，巢址必须提供有利于支持胚胎发育的条件。2019 年 7 月，在阿拉伯湾绿海龟的主要筑巢地卡兰岛（Karan Island），研究了绿海龟卵的孵化成功率和孵化环境。平均孵化成功率为 38.8%（范围为 2.5-75.0%，n=14）。早期胚胎死亡（EED）和晚期胚胎死亡（LED）的卵分别占卵窝的 19.8%（范围：3.3-64.2%）和 41.4%（范围：4.8-92.6%）。巢沙要么是粗沙（0.5-1 毫米：平均 44.8%，干重范围 30.4-56.9%，n=14），要么是中沙（0.25-0.5 毫米：平均 33.6%，干重范围 12.0-45.5%，n=14）。平均沙湿度（4.0%，范围 3.2-4.9%，n=14）处于成功发育的下限。沙含盐量<1500 EC.uS/cm（n=5）的卵窝孵化成功率显著高于 2500 EC.uS/cm（n=5）的卵窝。在 50 天产卵后，1200 小时的平均卵窝温度从 31.2°C升高到 36.6°C，平均升高了 5.4°C。胚胎除了受到盐度、湿度、沙粒大小等其他环境因素的影响外，还经历了致命的高温，这与孵化成功率降低有关。保护倡议必须考虑到上述参数的协同影响，制定战略，以提高阿拉伯湾绿海龟种群对人为和气候变化相关压力的整体恢复力。
